INTRO: The pursuit of the extreme is one of the latest trends in American sports. Whether it's skiing down slopes you can only get to by helicopter[degrees] kayaking down waterfalls[degrees] or climbing up sheer cliffs that have never been scaled before, athletes are constantly trying to 'push the envelope.' In the new sport of Muni (MEW-nee), riders must use intense concentration and superb balance as they navigate up and down steep rocky slopes. Charles Michael Ray takes us Mountain Unicycling.

TEXT: It's a windy day on the high desert of central Utah... the spring sun has melted the last bit of winter snow off the smooth sandstone ridges and the rugged desert terrain rolls on to the horizon in every direction.

AUDIO: CUT 1 CROWD AMBI Start to fade up and under

TEXT: A large crowd is gathered on one of the steep slopes of crimson sandstone. Many are wearing helmets and protective body armor. At their sides, they hold tough-looking beefed-up unicycles. This is the 2004 Moab Muni Fest. With 135 riders, it is the largest mountain unicycle event in the world to date. And one of the main contests is just beginning...

AUDIO: CUT 2 EVENT ORGANIZER

The Cliffs of Insanity is next! Any expert riders, come this way if you want to take part in the Cliffs of Insanity! The Cliffs of Insanity is starting now.

AUDIO: CUT 3 AMBI pedaling and people walking and talking (use as bed throughout as needed)

TEXT: Someone would have to be insane to try to ride up this ten-meter slope. The sandstone is broken by a rough series of steps and ledges[degrees] the bottom ledge drops off into a sheer twenty-meter cliff with a patch of cactus and pine trees below. The riders mount their unicycles.

TEXT: These unicycles are very different from those typically seen at a circus. They have extra-wide tires and reinforced frames that have been designed to take this kind of abuse, even if the riders cannot.

AUDIO: CUT 5 EVENT AMBI

CHINK -- OOOOO Aaaaa

TEXT: Only one contestant makes it up the first series of treacherous leaps, safely traverses back across the slope and then finally completes a careful set of hops and pedal strokes to reach the top of the Cliffs of Insanity.

AUDIO: CUT 6 EVENT AMBI

silence - hop hop hop. UGHHH - HURAHAA!! ALL-RIGHT! HUGE APPLAUSE

TEXT: This is Kris Holm, multi-time world champion, owner of his own line of specially outfitted mountain unicycles, and one of the pioneers of the sport known as Muni.

AUDIO: CUT 7 HOLM

Even though it's sloping and it's pretty smooth there's always irregularities in the rock and you really want to position your tire precisely in each of them and you can never be to greedy because if you're greedy you slip. You just incrementally work your way up the slope.

TEXT: The best Muni riders can jump off 3 meter ledges with ease, leap over a one and a half meter obstacle, and hop across a 3 meter gap. They can ride on virtually any terrain -- but they do so rather slowly... at about the pace of a rapid jog. Kris Holm says Mountain Unicycling is more like rock climbing than mountain biking, in that it takes intense concentration to stay on top of the wheel.

AUDIO: CUT 8 HOLM

Because of the precision involved it's a practice-oriented sport. You can have a great time on an easy trail or you can push yourself technically on the same hard terrain that mountain bikers use.

TEXT: The sport of Muni got rolling in 1996, when about 35 riders gathered in the foothills of California's Sierra Nevada Range for a weekend of unicycling through the back country. Since then, the sport has seen steady growth with the number of participants roughly doubling each year. California computer programmer John Foss organized that first Muni-Fest and is recognized as one of the sport's founding fathers. Foss says it's the challenge that draws many to off-road unicycling.

AUDIO: CUT 9 FOSS

Unicycling seems to attract people who like stuff that is hard. People who like to work at tough things. If you ask these people what they do for jobs or what they do in school, you'll find a lot of people who excel, or work with computers or who invent things and so it attracts an interesting crowd of people.

TEXT: Even though it's been around for less than a decade, many of the sport's biggest challenges have already been met -- including riding through parts of the tallest mountain range in the world. Mountain Unicycle enthusiast Nathan Hoover spent several weeks in 2002 crisscrossing the Himalayan kingdom of Bhutan with world Champion Kris Holm. They hiked up to remote monasteries in steep mountain passes and rode down the treacherous and ancient paths into secluded valleys. Hoover says the chance to travel by unicycle is part of what draws him to this sport.

AUDIO: CUT 10 HOOVER

I just like the way you can take your unicycle anywhere in the world, very easily. I like the way it's a little bit different. You get noticed. When you're traveling in foreign countries or anywhere it's instant passport to talk with people. And they come flocking up to you, and that's just a great thing.

TEXT: Hoover, who works for a California software company, says one reason unicycles are rarely seen is that not many people have learned to ride them. It takes an average of fifteen hours to master riding a unicycle just 10 meters without falling off.

AUDIO: CUT 11 HOOVER

You can get on a skateboard and do something right away, you can get on a bike and do something right away. Whereas a unicycle's gonna take, I don't know -- how good are you? Hours, weeks, months, to get going at all and then to do what people are doing here in the mountains. And then to do what people are doing in the mountains took me months to be able to go at all.

TEXT: While the learning curve for Mountain Unicycling is fairly steep, more and more people are taking the challenge. Retailers say the demand for off-road unicycles has grown dramatically in recent years and gatherings like the Moab Muni Fest are becoming more popular each year. World champion Kris Holm says it feels good to be at the top of an emerging sport.

AUDIO: CUT 12 HOLM

It's a really rare opportunity to be at the beginning of a sport and to get a chance to develop some of the techniques that even now people are taking for granted basically. And that's an exciting time. It's always the coolest part of any sport, I think, when it's really grassroots. You know everybody that's involved and you see a sport that you believe in grow and get bigger and bigger.

TEXT: Kris Holm's next adventure is to ride his unicycle down several peaks in the Andes Mountains of South America. For Main Street, I'm Charles Michael Ray in Moab Utah